In a typical cellular system, also referred to as a radio communications system, wireless terminals, also known as mobile stations and/or User Equipment units (UEs) communicate via a Radio Access Network (RAN) to one or more core networks. The wireless terminals can be mobile stations or user equipment units such as mobile telephones also known as “cellular” telephones, and laptops with wireless capability, e.g., mobile termination, and thus can be, for example, portable, pocket, hand-held, computer-included, or car-mounted mobile devices which communicate voice and/or data with radio access network.
The radio access network covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g., a Radio Base Station (RBS), which in some networks is also called “NodeB” or “B node” and which in this document also is referred to as a base station. A cell is a geographical area where radio coverage is provided by the radio base station equipment at a base station site. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. The base stations communicate over the air interface operating on radio frequencies with the user equipment units within range of the base stations.
In some versions of the radio access network, several base stations are typically connected, e.g., by landlines or microwave, to a Radio Network Controller (RNC). The radio network controller, also sometimes termed a Base Station Controller (BSC), supervises and coordinates various activities of the plural base stations connected thereto. The radio network controllers are typically connected to one or more core networks.
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile communication system, which evolved from the Global System for Mobile Communications (GSM), and is intended to provide improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. UMTS Terrestrial Radio Access Network (UTRAN) is essentially a radio access network using wideband code division multiple access for user equipment units (UEs). The Third Generation Partnership Project (3GPP) has undertaken to evolve further the UTRAN and GSM based radio access network technologies.
Being “green” has quickly gone from just a marketing hype to a key requirement for customers. This is true today for almost all sectors in society and the telecom market is no exception. The world today is facing a global energy crisis as people start to realize that our carbon based economy is no longer sustainable. Two areas that will become significant parts of a future sustainable economy are energy savings and telecommunications. Energy savings are by far the quickest and cheapest way of reducing carbon dioxide emissions to the atmosphere and telecommunication can significantly reduce the need for physical transportation of people and services. In 3rd Generation Partnership Project (3GPP) the work on the first release of the 3G Long Term Evolution (LTE) system, denoted LTE Rel-8 in 3GPP jargon, was finalized during 2008. The specifications of the next releases (denoted LTE Rel-9 and LTE Rel-10) are expected to be available 2009 and 2010 respectively. In LTE Rel-8 the maximum bandwidth is 20 MHz while in Rel-10 support for aggregation of multiple component carriers resulting in a total bandwidth of up to 100 MHz is expected to be specified, which LTE Rel-8 system and later releases of the LTE system all consume power.